late 14c., from Old French transposer (14c.), from Latin transponere (past participle transpositus) "to place over," from trans- "over" (see trans-) + ponere "to put, place" (see position). Form altered in French on model of poser "to put, place." Sense of "put music in a different key" is from c.1600. Related: Transposed; transposing.

(trāns-pōz') To move a term or quantity from one side of an algebraic equation to the other by adding or subtracting that term to or from both sides. By subtracting 2 from both sides of the equation 2 + x = 4, one can transpose the 2 to the other side, yielding x = 4 - 2, and thus determine that x equals 2.